Locking chuck

ABSTRACT

A tool driver includes a housing and a rotatable drive shaft extending therefrom. A chuck for holding the tool includes a generally cylindrical body member having a nose section and a tail section. Each of a plurality of jaws is slidably positioned in one of a plurality of angularly disposed passageways in the body. Each jaw has a jaw face and threads formed thereon. A nut is in operative communication with the drive shaft so that the drive shaft rotationally drives the nut. The nut engages the jaw threads so that rotation of the nut moves the jaws axially within the passageways. A locking mechanism is mounted to at least one of the housing and the body and is selectively actuatable to a first operative position and a second operative position. In the first position, the locking mechanism rotationally locks the housing and the body with respect to each other. In the second, it permits relative rotation between the body and the housing.

BACKGROUND OF THE INVENTION

The present invention relates generally to powered tool drivers such aselectric or pneumatic power drivers. More particularly, the presentinvention relates to such drivers having a chuck of the keyless type.

Power tool drivers are well known. Although twist drills are the mostcommon tools on such drivers, the tools may also comprise screw drivers,nut drivers, burrs, mounted grinding stones, and other cutting orabrading tools. Since the tool shank may be of varying diameter or ofpolygonal cross section, the device is usually provided with a chuckthat is adjustable over a relatively wide range. The chuck may beattached to the driver by a threaded or tapered bore or any othersuitable means.

A variety of chuck types have been developed that are actuated byrelative rotation between a chuck body and an annular nut. In a typicaloblique jawed chuck, for example, a body member includes threepassageways disposed approximately 120° apart from each other. Thepassageways are configured so that their center lines meet at a pointalong the chuck axis forward of the chuck body. Three jaws areconstrained by and movable in the passageways to grip a cylindrical toolshank disposed approximately along the chuck's center axis. The nutrotates about the chuck's center and engages threads on the jaws so thatrotation of the nut moves the jaws in either direction in thepassageways. The body and nut are configured so that rotation of the nutin one direction (the closing direction) with respect to the body forcesthe jaws into gripping relationship with the tool shank, while rotationin the opposite direction (the opening direction) releases the grippingrelationship. Such a chuck may be keyless if it is rotated by hand.Examples of such chucks are disclosed in U.S. Pat. Nos. 5,125,673 and5,193,824, commonly assigned to the present assignee and the entiredisclosure of each of which is incorporated by reference herein. Variousconfigurations of keyless chucks are known in the art and are desirablefor a variety of applications.

Keyless chucks actuated by relative rotation between a nut and a chuckbody include means to control the rotational position of the nut and thebody. For example, a first sleeve may be provided in communication withthe nut while a second sleeve, which is independent of the first sleeve,may be attached to the body. Thus, a user may rotate the first sleevewith one hand while gripping the second sleeve with the other hand,thereby holding the body still. Alternatively, in some devices in whichonly a single sleeve is provided, a user may grip the single sleeve andactuate the tool driver to rotate the spindle, thereby rotating thechuck body with respect to the sleeve. In addition, a mechanism may belocated in a driver to lock the spindle of the driver when the driver isnot actuated, thus enabling use of a single sleeve chuck.

SUMMARY OF THE INVENTION

The present invention recognizes and addresses problems concerningdrivers with hand operated chucks. Thus, broadly speaking, a principalobject of this invention is an improved driver and keyless chuckarrangement.

Additional objects and advantages of the invention are set forth or willbe apparent to those of ordinary skill in the art from the detaileddescription herein. Also, it should be further appreciated thatmodifications and variations to the specifically illustrated anddiscussed features may be practiced in various embodiments and uses ofthis invention without departing from the spirit and scope thereof, byvirtue of present reference thereto. Such variations may include, butare not limited to, substitution of equivalent means and features forthose shown or discussed, and the functional or positional reversal ofvarious parts, or the like.

These and other objects may be achieved by a driver having a housing,rotatable drive shaft and a chuck. The chuck has a generally cylindricalbody member with a nose section having an axial bore formed therein. Thebody has a plurality of angularly disposed passageways formed therein sothat each of a plurality of jaws may be slidably positioned respectivelytherein. Each of the jaws has a face and threads formed thereon. A nutis in operative communication with the drive shaft and the threads onthe jaws so that the drive shaft rotationally drives the nut withrespect to the body to move the jaws axially within the passageways. Alocking mechanism mounted to at least one of the housing and the bodyhas two operative positions. The first rotationally locks the body andthe housing with respect to one another. The second permits relativerotation between the body member and the housing.

In one preferred embodiment of the present invention, a chuck for usewith a driver having a housing and a rotatable drive shaft includes agenerally cylindrical body member having a nose section with an axialbore formed therein. The body has a plurality of angularly disposedpassageways formed therein so that each of a plurality of jaws may beslidably positioned respectively therein. Each of the jaws has a faceand threads formed thereon. A nut is in operative communication with thedrive shaft and the threads on the jaws so that the drive shaftrotationally drives the nut so that the rotation of the nut with respectto the body moves the jaws axially within the passageways. A lockingmechanism mounted to at least one of the housing and the body has twooperative positions. The first rotationally locks the body and thehousing with respect to one another. The second permits relativerotation between the body member and the housing.

Those of ordinary skill in the art will better appreciate the featuresand aspects of such embodiments, and others, upon review of thespecification.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 is a longitudinal view, partly in section, of a chuck inaccordance with an embodiment of the present invention;

FIG. 2 is a longitudinal view, partly in section, of the chuck as inFIG. 1;

FIG. 3 is a perspective view, partly in section, of the chuck as in FIG.1;

FIG. 4 is an exploded view of the chuck as in FIG. 1;

FIG. 5A is a longitudinal view, partly in section, of a chuck inaccordance with an embodiment of the present invention;

FIG. 5B is an enlarged view of the section indicated in FIG. 5A in whicha sleeve is riding over a detent mechanism; and

FIG. 5C is an enlarged view of the section indicated in FIG. 5A in whicha sleeve has passed over a detent mechanism.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference will now be made in detail to presently preferred embodimentsof the invention, one or more examples of which are illustrated in theaccompanying drawings. Each example is provided by way of explanation ofthe invention, not limitation of the invention. In fact, it will beapparent to those skilled in the art that modifications and variationscan be made in the present invention without departing from the scope orspirit thereof. For instance, features illustrated or described as partof one embodiment may be used on another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncover such modifications and variations as come within the scope of theappended claims and their equivalents.

A power drill according to the present invention is indicated in thefigures in phantom by a drill housing 30 and a drive shaft 28. Althoughit may be possible to utilize the present invention within a non-powereddrill, power drivers such as electric and pneumatic drivers arepreferred. Moreover, any suitable power driver may be employed withinthe present invention and should be well understood in this art.Accordingly, for purposes of clarity, the drill is indicated in theFigures only by the housing and drive shaft.

In one preferred embodiment illustrated in FIGS. 1-4, a drill chuck ismated to the spindle and has a body having passageways in which jaws areheld. The jaws reciprocally move (in either an opening or a closingdirection) by a threadedly engaged nut. A locking mechanism, in the formof a generally cylindrical sleeve, is axially movable to either of twopositions. In the first position, the sleeve rotationally locks the bodyto the driver housing. Because the nut may still freely rotate withrespect to the body, however, actuation of the drive shaft causesrelative rotation between the nut and the body to open or close thechuck, depending on the drive shaft's rotational direction. In thesecond position, the body and the sleeve are rotatable with respect tothe drill housing.

Referring to FIG. 1, the sleeve is in the second position, and it andbody may freely rotate with respect to the driver housing. In FIG. 2,the sleeve is in the first position, engaging the driver housing so thatthe driver housing, sleeve and body are rotationally locked together.

As also shown in the figures, a drive spindle rotationally drives thenut through a clutch mechanism. The clutch mechanism rotationally locksthe spindle to the nut as long as the nut does not substantially resistthe rotational torque applied by a spindle ring as described in moredetail below. When the resistance does overcome this torque, teeth onthe nut and the spindle ring slip over each other. The nut and spindlethen rotate with respect to each other so that there is an impact whenthe following teeth on the nut and the spindle ring engage. At highspindle rotational speeds, successive impacts further tighten the chuck.At the same time, however, the slip allowed by the clutch preventsdamage to the driver and chuck components if the spindle is activatedfor too long a period.

Referring again to FIG. 1, a chuck 10 includes a body 12, a rear sleeve20, a spindle ring 14, a locking ring 48, and a nut 18. Body 12 isgenerally cylindrical in shape and comprises a nose or forward section80 and a tail or rearward section 82. An axial bore 24 is formed in thenose section 80 and is dimensioned somewhat larger than the largest toolshank that the chuck is designed to accommodate.

Jaw guideways 42 are formed in body 12 to accommodate each jaw 16. Threejaws 16 are employed, and each jaw is separated from the adjacent jaw byan arc of approximately 120 degrees. The axes of the jaw guideways 42and the jaws 16 are angled with respect to the chuck axis and intersectthe chuck axis at a common point ahead of chuck body 12. Each jaw 16 hasa tool engaging portion 34, which is generally parallel to the axis ofthe chuck body 12, and threads 36. Threads 36 may be constructed in anysuitable type and pitch.

Nut 18 is a one-piece nut which includes threads 44 for mating withthreads 36 on jaws 16. Nut 18 is positioned in the body in engagementwith the jaw threads so that when the nut is rotated with respect to thebody 12, the jaws will be advanced or retracted. An outer cone formed bythe nut threads forms an approximately 15 degree angle with respect tothe chuck axis.

The outer circumferential surface of locking ring 48 may be knurled ormay be provided with longitudinal ribs or any other configuration toenable a user to grip it securely. The sleeve may be fabricated fromsteel or a structural plastic such as polycarbonate, a filledpolypropylene, for example glass-filled polypropylene, or a blend ofstructural plastic materials. Other composite materials such as, forexample, graphite-filled polymerics, may also be suitable in a givenenvironment. In one embodiment, the sleeve is constructed from the 30percent glass-filled nylon material. As would be appreciated by oneskilled in the art, materials for which the chuck of the presentinvention is fabricated will depend on the end use of the chuck, and theabove are provided by way of example only.

Referring also to FIGS. 3 and 4, nut 18 includes a plurality of teeth 58which engage teeth 62 on spindle ring 14. In the illustrated embodiment,two teeth 58 and two teeth 62 are provided. Spindle ring 14 is threadedonto the drive shaft and rotationally drives the nut through teeth 58and 62.

A locking mechanism includes a cylindrical sleeve comprising rear sleeve20 and locking ring 48. Locking ring 48 is axially and rotationallyfixed to rear sleeve 20. The cylindrical sleeve is axially reciprocalwith respect to body 12 and is retained in either of two axial positionsby a detent mechanism 46. In the embodiment of the present inventionshown in FIGS. 1-4, detent mechanism 46 includes a coil spring 64biasing a ball 66 into either of two annular slots 54 and 56 in lockingring 48. Each of slots 54 and 56 may be formed continuously around theinner arcuate surface 78 of locking ring 48 so as to provide ease ofalignment. Although only one pair is shown in the figures, a pluralityof balls 66 and respective springs 64 may be provided around the body.With the sleeve in the forward position shown in FIG. 1, detentmechanism 46 engages slot 54 and thereby holds locking ring 48 and rearsleeve 20 away from drill housing 30.

Rear sleeve 20 is rotationally locked to the body 12 by ribs 74 (FIGS. 3and 4) received in grooves 72. Referring to the forward axial positionof sleeve 20 in FIG. 1 and also referring to FIGS. 3 and 4, rear sleeve20 rotationally locks to spindle ring 14 through the engagement of teeth70 at the rear end of sleeve 20 and teeth 60 about the spindle ring'souter circumference. The spindle ring is, in turn, rotationally lockedto spindle 28. Thus, spindle 28 rotationally drives body 12 when therear sleeve is in its forward position.

Spindle ring 14 is generally cylindrical in shape and comprises a noseor forward section 84 and a tail or rearward section 86. An axial bore88 is made in nose section 84. A threaded bore 26 is formed in tailsection 86 and is of a standard size to mate with drive shaft 28 of thepowered driver indicated in part at 30. The bores 26 and 88 maycommunicate at a central region of spindle ring 14. While a threadedbore 26 is illustrated, the spindle ring could include a tapered bore ofa standard size to mate with a tapered drive shaft or with any othersuitable connection mechanism.

When sleeve 20 is pulled rearwardly from the forward axial positionshown in FIG. 1, the forward edge of slot 54 depresses balls 66 againstsprings 64 so that the springs compress, thereby allowing locking member48 to ride over the balls. As the sleeve continues its rearwardmovement, teeth 70 disengage teeth 60, and rear sleeve 20 moves into arearward position as shown in FIG. 2. The rear sleeve receives studs 50into recesses 52 to rotationally lock the rear sleeve with respect todriver housing 30, and second slot 56 receives balls 66 to axiallyretain the rear sleeve in position.

Thus, body 12 is rotationally locked to housing 30 through theengagement of ribs 74 and grooves 72 (FIGS. 3 and 4) in body 12 andsleeve 20, respectively, and through the engagement of studs 50 andrecesses 52 in sleeve 20 and housing 30, respectively. Because of thedisengagement of teeth 70 from teeth 60, however, spindle ring 14 isrotatable with respect to the body.

A bearing assembly and clutch mechanism includes a clutch spring 22bearing on one side against spindle ring 14 and on the other against abearing ring 40. Since spindle ring 14 is mated to spindle 28, spring 22biases bearing ring 40 rearward against a retaining clip 38 received inan annular slot in body 12, thereby biasing body 12 axially rearwardwith respect to the spindle. Body 12 therefore pushes nut 18 rearwardagainst spindle ring 14. Thus, activation of spindle 28 (FIG. 1) rotatesspindle ring 14 which, in turn, rotates nut 18 by teeth 58 and 62 (FIG.4). When the body is rotationally locked to the drill housing as in FIG.2, nut 18 therefore rotates relative to body 12, opening or closing thechuck depending on the spindle's rotational direction.

Referring now to FIG. 4, teeth 58 define sides 68 that oppose sides onteeth 62 that are substantially parallel to sides 68. Each side 68 isdisposed at an approximately 30 degree angle with respect to a plane 92that includes chuck axis 94. Thus, rotational force applied by spindlering 14 to nut 18 tends to urge teeth 58 to ride over teeth 62. When thechuck is not fully opened or closed, the axial force applied by spring22 overcomes this tendency, and the nut rotates with the spindle ring.

When the chuck fully closes (with or without an inserted tool) or fullyopens, however, further rotation of nut 18 is resisted. This resistanceovercomes the bias of spring 22, and teeth 58 ride over teeth 62,pushing nut 18 and body 12 axially forward.

When teeth 58 pass over teeth 62, clutch spring 22 returns bearingassembly 40 to its original axial position. This produces successiveblows against the nut as the next set of teeth engage, thereby furthertightening the chuck, or loosening the chuck if it is overtightened. Thehammer effect is noticeable to the operator and therefore indicates thatjaws 16 have fully tightened on the operative workpiece or that thechuck has fully opened.

Referring also to FIG. 2, the reciprocal movement of body 12 due to therelative slip between the nut and spindle ring does not disengage rearsleeve 20 from drill housing 30. Slot 56 is slightly wider than thediameter of balls 66 so that the balls can move axially forward withbody 12 without moving locking member 48 and sleeve 20. Thus, the excesswidth should be at least equal to the distance body 12 moves. Shouldfrictional forces nevertheless carry the locking member and sleeveforward with the body, or if slot 56 includes no extra axial width toallow movement of balls 46, studs 50 are long enough to prevent thesleeve's disengagement. That is, the length of studs 50 extending intorecesses 52 is greater than the forward axial movement of body 12.

FIGS. 5A-5C illustrate a chuck 10 having a detent mechanism differentfrom that shown in FIGS. 1-4. Specifically, a C-shaped clip spring 96 isreceived in an outer annular groove in spindle ring 14 and has an outerdiameter greater than the outer diameter of the spindle ring's rear end.Further, the outer diameter of spring 96 is greater than the innerdiameter of a rear flange 98 of sleeve 20. Thus, spring 96 retains rearsleeve 20 in its rearward axial position as shown in FIG. 5A.

Referring to FIG. 5B, when the rear sleeve is moved forward (asindicated by arrow 100) to disengage the rear sleeve from studs 50,flange 98 compresses spring 96 down into the spindle ring groove. Whenflange 98 passes over spring 96, as shown in FIG. 5C, the resilientspring expands back to its original position and thereafter retains therear sleeve in the forward axial position. As shown in the figures, theedges of flange 98 may be beveled to assist in riding over spring 96.

Since the detent mechanism of FIGS. 5A-5C acts between the spindle ringand rear sleeve rather than between the chuck body and the rear sleeve,there is less likelihood that the rear sleeve will be pulled forwardwith the chuck body when the nut and spindle ring slip with respect toeach other. However, studs 50 may still extend far enough into recesses52 to prevent disengagement of the rear sleeve from the drill housing incase forward movement of the rear sleeve should nevertheless occur.

While one or more preferred embodiments of the present invention aredescribed above, it should be appreciated that various suitableembodiments are encompassed by the present invention. For example, thelocking mechanism shown in the FIGS. may be replaced by any suitablemechanism such as a sleeve or lever mounted on the drill housing andselectively extendable rearward to engage the body so that the body andhousing are rotationally locked with respect to each other. Furthermore,many variations in the placement, configuration, and operation of themechanisms that rotationally and axially lock one element of the chuckto another may be realized.

Moreover, it should be understood by those skilled in the art that thechuck components described above may be arranged and configured invarious suitable manners within the present invention. Variousmodifications and variations to the present invention may be practicedby those of ordinary skill in the art without departing from the spiritand scope of the present invention, which is more particularly set forthin the appended claims. In addition, it should be understood thataspects of the various embodiments may be interchanged both in whole orin part. Furthermore, those of ordinary skill in the art will appreciatethat the foregoing description is provided by way of example only and isnot intended to be limitative of the invention so further described insuch appended claims.

What is claimed is:
 1. A chuck for use with a driver having a housingand a rotatable drive shaft extending therefrom, the chuck comprising: agenerally cylindrical body member having a nose section with an axialbore formed therein and a plurality of angularly disposed passagewaysformed therethrough and intersecting the axial bore; a plurality ofjaws, each jaw being slidably positioned in a respective one of theangularly disposed passageways and having a jaw face and threads formedthereon; a nut in operative communication with the drive shaft so thatthe drive shaft rotationally drives the nut, the nut engaging thethreads on the jaws so that rotation of the nut with respect to the bodyaxially moves the jaws within the passageways; and a locking mechanismselectively actuatable to a first operative position in which thelocking mechanism rotationally locks the housing and the body memberwith respect to each other, and a second operative position in which thelocking mechanism permits relative rotation between the body member andthe housing.
 2. The chuck as in claim 1, wherein said locking mechanismis mounted to the chuck.
 3. The chuck as in claim 1, wherein a spindlering is attached to the spindle and drives the nut through interengaging teeth on the spindle ring and the nut.
 4. The chuck as in claim1, wherein the locking mechanism includes an axially reciprocal sleeve.5. The chuck as in claim 2, wherein the locking mechanism includes anaxially reciprocal sleeve and wherein the sleeve engages the spindle sothat the sleeve is rotationally locked to the spindle in the secondoperative position.
 6. The chuck as in claim 5, wherein the sleeve inthe second operative position is rotationally locked to the body.
 7. Thechuck as in claim 4, wherein the sleeve is rotationally locked to thebody in the first operative position and in the first operative positionand is rotationally locked to the housing in the first operativeposition so that the sleeve rotationally locks the body to the housing.8. The chuck as in claim 1, including a biasing mechanism and a clutchmechanism operatively between the nut and the spindle, the biasingmechanism biasing the nut and the spindle together and the clutchmechanism rotationally disengaging the nut and the spindle when the jawsreach a fully closed position.
 9. The chuck as in claim 8, including aspindle ring disposed between the spindle and the nut.
 10. A chuck foruse with a driver having a housing and a rotatable drive shaft extendingtherefrom, the chuck comprising: a generally cylindrical body memberhaving a nose section with an axial bore formed therein, a plurality ofangularly disposed passageways formed therethrough intersecting theaxial bore; a plurality of jaws, each jaw being slidably positioned in arespective one of the angularly disposed passageways and having a jawface and threads formed thereon; a nut rotatably mounted adjacent to thebody in engagement with the threads on the jaws so that rotation of thenut moves the jaws axially within the passageways; a generallycylindrical rear sleeve member having a nose and a tail section, thetail section rotationally locked to the body member and axiallyreciprocal between a first position in which the rear sleeve isrotationally locked to the housing and a second position in which therear sleeve is rotatable with respect to the housing; a locking ringmounted to the rear sleeve and selectively engagable to the body memberto axially retain the rear sleeve in the first position and the secondposition a spindle ring having a threaded axial bore to receive thedrive shaft and a first end and a second end wherein the first end hasteeth which interlock with mating teeth on the nut and may disengage toallow the spindle ring to rotate freely with respect to the nut, thesecond end has teeth which interlock with mating teeth on the rearsleeve rotationally locking the rear sleeve to the spindle ring; and aclutch spring operatively located on the spindle ring and biasing thenut and spindle ring together so that when the nut disengages from thespindle ring moving the body in the axial direction, the clutch springreturns the nut and body to their original axial position.
 11. A tooldriver, said driver comprising: a housing; a rotatable drive shaft; achuck including a generally cylindrical body member having a nosesection with an axial bore formed therein and a plurality of angularlydisposed passageways formed therethrough and intersecting the axialbore, a plurality of jaws, each jaw being slidably positioned in arespective one of the angularly disposed passageways and having a jawface and threads formed thereon, a nut in operative communication withthe drive shaft so that the drive shaft rotationally drives the nut, thenut engaging the threads on the jaws so that rotation of the nut withrespect to the body axially moves the jaws within the passageways; and alocking mechanism mounted to at least one of the housing and the bodymember and selectively actuatable to a first operative position in whichthe locking mechanism rotationally locks the housing and the body memberwith respect to each other, and a second operative position in which thelocking mechanism permits relative rotation between the body member andthe housing.
 12. The driver as in claim 11, including a generallycylindrical spindle ring mated with the drive shaft and in rotationallydriving engagement with the nut.
 13. The driver as in claim 11, whereinthe locking mechanism includes an axially reciprocal sleeve mounted onthe chuck.
 14. The driver as in claim 12, wherein the locking mechanismincludes an axially reciprocal sleeve mounted on the chuck, and whereinthe sleeve engages the spindle ring so that the sleeve is rotationallylocked to the spindle ring in the second operative position.
 15. Thedriver as in claim 14, wherein the sleeve in the second operativeposition is rotationally locked to the body.
 16. The driver as in claim13, wherein the sleeve is rotationally locked to the body in the firstoperative position and in the first operative position and isrotationally locked to the housing in the first operative position sothat the sleeve rotationally locks the body to the housing.
 17. Thedriver as in claim 16, wherein the sleeve includes axially extendingribs slidably received within axially extending grooves on the body andwherein the sleeve includes annularly disposed teeth interlockinglyreceived in the first operative position by annularly disposed teeth onthe housing, the sleeve teeth disengaging the housing teeth in thesecond operative position.
 18. The driver as in claim 12, including abiasing mechanism and a clutch mechanism operatively between the nut andthe spindle ring, the biasing mechanism biasing the nut and spindle ringtogether and the clutch mechanism rotationally disengaging the nut andspindle when the jaws reach a fully closed position.
 19. The driver asin claim 18, wherein the clutch includes at least one axially extendedtooth on the spindle ring interlocking with an axially extending toothon the nut.
 20. The driver as in claim 19, wherein the nut tooth has aside disposed at an oblique angle with respect to a plane including thechuck axis, and wherein the spindle ring tooth has a side opposing andsubstantially parallel to the nut tooth side.
 21. The driver as in claim20, wherein the biasing mechanism includes a spring bearing on the bodyand the spindle ring and biasing the body rearward with respect to thespindle ring.
 22. The driver as in claim 13, wherein the housingincludes a plurality of pins extending axially therefrom and wherein thesleeve includes a plurality of holes receiving the pins in the firstoperative position.
 23. The driver as in claim 11, including a detentmechanism disposed in the body and configured to releasably hold thesleeve in each of the first and second operative positions.